When performing a treatment on an alimentary tract affected by cancer or the like within a human body, an endoscopic mucosal resection operation has been conducted in which an endoscope is inserted into the body through the mouth or the anus so as to resect a lesion. In such an operation, all layers including the affected mucosal layer and the muscular layer have been resected. However, perforations may be formed in the alimentary tract by resecting the entire layer. Thus, it is necessary to suture the perforations using an endoscopic treatment system including a suturing device in order to prevent the lumen of the alimentary tract from coalescing with the abdominal cavity via the perforations.
An endoscopic treatment system employed in such a case is provided with an overtube through which an endoscope can be inserted. The overtube has a lateral opening formed at the distal end thereof, through which all layers including the lesion are drawn and are subjected to a suture treatment. Thereafter, all layers are resected by a high-frequency snare or the like. At the time of the suture treatment, in the vicinity of the opening, a ligating tool (or a suture thread) is penetrated through all layers of the tract from the front side toward the back side thereof so that the tract including the lesion is deformed like a pouch. As a result, the front side and the back side of the tissue around the lesion are overlapped with each other. Thus, it is possible to prevent the lumen of the tract from coalescing with the abdominal cavity even when the entire lesion is resected.
JP-A-2004-65679 is an example of the prior art.
However, such an endoscopic treatment system has the following problems.
When other organs are positioned adjacent to a portion to be resected, the procedure should be performed while preventing other organs from being sutured at the time of suturing the alimentary tract. Accordingly, it has been one of the reasons for the procedure being complicated.
In addition, since the opening is formed on the lateral surface of the overtube, it is difficult to capture the image of the lesion using an image capturing portion provided at the distal end of the endoscope. Thus, it is difficult to identify the position of the lesion, deteriorating the operability of a treatment tool such as the suturing device.
Although the ligating tool or the suture thread is passed through the alimentary tract so as to substantially overlap with the same, it is difficult to maintain a closed environment until the biological tissue is coalesced.